Aspects of the present disclosure relate generally to fiber optic cables and components thereof, and more specifically to buffer tubes containing one or more optical fibers as may be part of the fiber optic cables.
Buffer tubes in fiber optic cables typically contain optical fibers and protect the fibers from various mechanical stresses induced either at installation of the cable or occurring during use over the lifetime of the cable, such as compression forces, impacts, and bending stresses. Therefore, buffer tubes should be formed from a material with high modulus, to have high compression resistance. However, buffer tubes should also be designed to retain flexibility, such that the buffer tube can be routed easily and stored in small coils. Conventional buffer tube designs may have good crush performance but insufficient flexibility, or vice versa. Some conventional designs are also susceptible to effects of hydrolysis, resulting in brittleness. Some conventional buffer tube materials have issues with shrinking over time, called “shrink back,” and/or are formed with materials having poor dimensional stability with changes in temperature, which may limit the size of buffer tubes to be wide enough to not, at times, constrict around the optical fibers and/or pull away from connectors attached to the fibers.
A need exists for a fiber optic assembly including a buffer tube that sufficiently protects optical fibers therein from compressive stresses, while retaining high flexibility and impact resistance. Ideally, the buffer tube should have good performance with respect to hydrolysis and not excessively attenuate the optical fibers due to temperature-related expansion or contraction of the buffer tube in the field.